1. 12 Sep, 2017 1 commit
  2. 23 Jul, 2017 1 commit
  3. 31 Mar, 2017 1 commit
    • Ben Gamari's avatar
      Clean up coreView/tcView. · 6575f4b6
      Ben Gamari authored
      In Core, Constraint should be considered fully equal to
      TYPE LiftedRep, in all ways. Accordingly, coreView should
      unwrap Constraint to become TYPE LiftedRep. Of course, this
      would be a disaster in the type checker.
      
      So, where previously we used coreView in both the type checker
      and in Core, we now have coreView and tcView, which differ only
      in their treatment of Constraint.
      
      Historical note: once upon a past, we had tcView distinct from
      coreView. Back then, it was because newtypes were unwrapped in
      Core but not in the type checker. The distinction is back, but
      for a different reason than before.
      
      This had a few knock-on effects:
      
       * The Typeable solver must explicitly handle Constraint to ensure
         that we produce the correct evidence.
      
       * TypeMap now respects the Constraint/Type distinction
      
      Finished by: bgamari
      
      Test Plan: ./validate
      
      Reviewers: simonpj, austin, bgamari
      
      Reviewed By: simonpj
      
      Subscribers: rwbarton, thomie
      
      Differential Revision: https://phabricator.haskell.org/D3316
      6575f4b6
  4. 03 Mar, 2017 2 commits
    • Ben Gamari's avatar
      Produce KindReps for common kinds in GHC.Types · c1dacb8a
      Ben Gamari authored
      Unfortunately this comes with a fair bit of implementation cost. Perhaps
      some refactoring would help, but in the interest of getting 8.2 out the
      door I'm pushing as-is.
      
      While this doesn't have nearly the effect on compiler allocations
      that D3166 has, it's still nothing to sneeze at. nofib shows,
      ```
      ------------------------------------------------------------------------
              Program               master           D3166            D3219
      ------------------------------------------------------------------------
              -1 s.d.                -----          -3.555%          -4.081%
              +1 s.d.                -----          +1.937%          +1.593%
              Average                -----          -0.847%          -1.285%
      ```
      
      Test Plan: Validate
      
      Reviewers: austin
      
      Subscribers: thomie, simonmar
      
      Differential Revision: https://phabricator.haskell.org/D3219
      c1dacb8a
    • Ben Gamari's avatar
      TcTypeable: Try to reuse KindReps · a694cee7
      Ben Gamari authored
      Here we rework the TcTypeable implementation to reuse KindRep bindings
      when possible. This is an attempt at minimizing the impact of Typeable
      binding generation by reducing the number of bindings that we produce.
      
      It turns out that this produces some pretty reasonable compiler
      allocations improvements. It seems to erase most of the increases
      initially introduced by TTypeable in the testsuite. Moreover, nofib
      shows,
      ```
              -1 s.d.                -----          -3.555%
              +1 s.d.                -----          +1.937%
              Average                -----          -0.847%
      ```
      
      Here are a few of the high-scorers (ignore last column, which is for
      D3219),
      ```
      veritas
                Types             88800920         -18.945%         -21.480%
      
      veritas
              Tactics            540766744         -27.256%         -27.338%
      
      sched
                 Main            567013384          -4.947%          -5.358%
      
      listcompr
                 Main            532300000          -4.273%          -4.572%
      
      listcopy
                 Main            537785392          -4.382%          -4.635%
      
      anna
             BaseDefs           1984225032         -10.639%         -10.832%
      
      ```
      as expected, these tend to be modules with either very many or very
      large types.
      
      Test Plan: Validate
      
      Reviewers: austin, dfeuer
      
      Subscribers: simonmar, dfeuer, thomie
      
      Differential Revision: https://phabricator.haskell.org/D3166
      a694cee7
  5. 02 Mar, 2017 1 commit
  6. 18 Feb, 2017 1 commit
    • Ben Gamari's avatar
      Type-indexed Typeable · 8fa4bf9a
      Ben Gamari authored
      This at long last realizes the ideas for type-indexed Typeable discussed in A
      Reflection on Types (#11011). The general sketch of the project is described on
      the Wiki (Typeable/BenGamari). The general idea is that we are adding a type
      index to `TypeRep`,
      
          data TypeRep (a :: k)
      
      This index allows the typechecker to reason about the type represented by the `TypeRep`.
      This index representation mechanism is exposed as `Type.Reflection`, which also provides
      a number of patterns for inspecting `TypeRep`s,
      
      ```lang=haskell
      pattern TRFun :: forall k (fun :: k). ()
                    => forall (r1 :: RuntimeRep) (r2 :: RuntimeRep)
                              (arg :: TYPE r1) (res :: TYPE r2).
                       (k ~ Type, fun ~~ (arg -> res))
                    => TypeRep arg
                    -> TypeRep res
                    -> TypeRep fun
      
      pattern TRApp :: forall k2 (t :: k2). ()
                    => forall k1 (a :: k1 -> k2) (b :: k1). (t ~ a b)
                    => TypeRep a -> TypeRep b -> TypeRep t
      
      -- | Pattern match on a type constructor.
      pattern TRCon :: forall k (a :: k). TyCon -> TypeRep a
      
      -- | Pattern match on a type constructor including its instantiated kind
      -- variables.
      pattern TRCon' :: forall k (a :: k). TyCon -> [SomeTypeRep] -> TypeRep a
      ```
      
      In addition, we give the user access to the kind of a `TypeRep` (#10343),
      
          typeRepKind :: TypeRep (a :: k) -> TypeRep k
      
      Moreover, all of this plays nicely with 8.2's levity polymorphism, including the
      newly levity polymorphic (->) type constructor.
      
      Library changes
      ---------------
      
      The primary change here is the introduction of a Type.Reflection module to base.
      This module provides access to the new type-indexed TypeRep introduced in this
      patch. We also continue to provide the unindexed Data.Typeable interface, which
      is simply a type synonym for the existentially quantified SomeTypeRep,
      
          data SomeTypeRep where SomeTypeRep :: TypeRep a -> SomeTypeRep
      
      Naturally, this change also touched Data.Dynamic, which can now export the
      Dynamic data constructor. Moreover, I removed a blanket reexport of
      Data.Typeable from Data.Dynamic (which itself doesn't even import Data.Typeable
      now).
      
      We also add a kind heterogeneous type equality type, (:~~:), to
      Data.Type.Equality.
      
      Implementation
      --------------
      
      The implementation strategy is described in Note [Grand plan for Typeable] in
      TcTypeable. None of it was difficult, but it did exercise a number of parts of
      the new levity polymorphism story which had not yet been exercised, which took
      some sorting out.
      
      The rough idea is that we augment the TyCon produced for each type constructor
      with information about the constructor's kind (which we call a KindRep). This
      allows us to reconstruct the monomorphic result kind of an particular
      instantiation of a type constructor given its kind arguments.
      
      Unfortunately all of this takes a fair amount of work to generate and send
      through the compilation pipeline. In particular, the KindReps can unfortunately
      get quite large. Moreover, the simplifier will float out various pieces of them,
      resulting in numerous top-level bindings. Consequently we mark the KindRep
      bindings as noinline, ensuring that the float-outs don't make it into the
      interface file. This is important since there is generally little benefit to
      inlining KindReps and they would otherwise strongly affect compiler performance.
      
      Performance
      -----------
      
      Initially I was hoping to also clear up the remaining holes in Typeable's
      coverage by adding support for both unboxed tuples (#12409) and unboxed sums
      (#13276). While the former was fairly straightforward, the latter ended up being
      quite difficult: while the implementation can support them easily, enabling this
      support causes thousands of Typeable bindings to be emitted to the GHC.Types as
      each arity-N sum tycon brings with it N promoted datacons, each of which has a
      KindRep whose size which itself scales with N. Doing this was simply too
      expensive to be practical; consequently I've disabled support for the time
      being.
      
      Even after disabling sums this change regresses compiler performance far more
      than I would like. In particular there are several testcases in the testsuite
      which consist mostly of types which regress by over 30% in compiler allocations.
      These include (considering the "bytes allocated" metric),
      
       * T1969:  +10%
       * T10858: +23%
       * T3294:  +19%
       * T5631:  +41%
       * T6048:  +23%
       * T9675:  +20%
       * T9872a: +5.2%
       * T9872d: +12%
       * T9233:  +10%
       * T10370: +34%
       * T12425: +30%
       * T12234: +16%
       * 13035:  +17%
       * T4029:  +6.1%
      
      I've spent quite some time chasing down the source of this regression and while
      I was able to make som improvements, I think this approach of generating
      Typeable bindings at time of type definition is doomed to give us unnecessarily
      large compile-time overhead.
      
      In the future I think we should consider moving some of all of the Typeable
      binding generation logic back to the solver (where it was prior to
      91c6b1f5). I've opened #13261 documenting this
      proposal.
      8fa4bf9a
  7. 15 Dec, 2016 1 commit
  8. 07 Dec, 2016 1 commit
    • Alan Zimmerman's avatar
      Add HsSyn prettyprinter tests · 499e4382
      Alan Zimmerman authored
      Summary:
      Add prettyprinter tests, which take a file, parse it, pretty print it,
      re-parse the pretty printed version and then compare the original and
      new ASTs (ignoring locations)
      
      Updates haddock submodule to match the AST changes.
      
      There are three issues outstanding
      
      1. Extra parens around a context are not reproduced. This will require an
         AST change and will be done in a separate patch.
      
      2. Currently if an `HsTickPragma` is found, this is not pretty-printed,
         to prevent noise in the output.
      
         I am not sure what the desired behaviour in this case is, so have left
         it as before. Test Ppr047 is marked as expected fail for this.
      
      3. Apart from in a context, the ParsedSource AST keeps all the parens from
         the original source.  Something is happening in the renamer to remove the
         parens around visible type application, causing T12530 to fail, as the
         dumped splice decl is after the renamer.
      
         This needs to be fixed by keeping the parens, but I do not know where they
         are being removed.  I have amended the test to pass, by removing the parens
         in the expected output.
      
      Test Plan: ./validate
      
      Reviewers: goldfire, mpickering, simonpj, bgamari, austin
      
      Reviewed By: simonpj, bgamari
      
      Subscribers: simonpj, goldfire, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D2752
      
      GHC Trac Issues: #3384
      499e4382
  9. 13 Nov, 2016 1 commit
    • Ben Gamari's avatar
      Kill Type pretty-printer · 6c0f10fa
      Ben Gamari authored
      Here we consolidate the pretty-printing logic for types in IfaceType. We
      need IfaceType regardless and the printer for Type can be implemented in
      terms of that for IfaceType. See #11660.
      
      Note that this is very much a work-in-progress. Namely I still have yet
      to ponder how to ease the hs-boot file situation, still need to rip out
      more dead code, need to move some of the special cases for, e.g., `*` to
      the IfaceType printer, and need to get it to validate. That being said,
      it comes close to validating as-is.
      
      Test Plan: Validate
      
      Reviewers: goldfire, austin
      
      Subscribers: goldfire, thomie, simonpj
      
      Differential Revision: https://phabricator.haskell.org/D2528
      
      GHC Trac Issues: #11660
      6c0f10fa
  10. 21 Oct, 2016 1 commit
    • Simon Peyton Jones's avatar
      A collection of type-inference refactorings. · 3f5673f3
      Simon Peyton Jones authored
      This patch does a raft of useful tidy-ups in the type checker.
      I've been meaning to do this for some time, and finally made
      time to do it en route to ICFP.
      
      1. Modify TcType.ExpType to make a distinct data type,
         InferResult for the Infer case, and consequential
         refactoring.
      
      2. Define a new function TcUnify.fillInferResult, to fill in
         an InferResult. It uses TcMType.promoteTcType to promote
         the type to the level of the InferResult.
         See TcMType Note [Promoting a type]
         This refactoring is in preparation for an improvement
         to typechecking pattern bindings, coming next.
      
         I flirted with an elaborate scheme to give better
         higher rank inference, but it was just too complicated.
         See TcMType Note [Promotion and higher rank types]
      
      3. Add to InferResult a new field ir_inst :: Bool to say
         whether or not the type used to fill in the
         InferResult should be deeply instantiated.  See
         TcUnify Note [Deep instantiation of InferResult].
      
      4. Add a TcLevel to SkolemTvs. This will be useful generally
      
          - it's a fast way to see if the type
            variable escapes when floating (not used yet)
      
          - it provides a good consistency check when updating a
            unification variable (TcMType.writeMetaTyVarRef, the
            level_check_ok check)
      
         I originally had another reason (related to the flirting
         in (2), but I left it in because it seems like a step in
         the right direction.
      
      5. Reduce and simplify the plethora of uExpType,
         tcSubType and related functions in TcUnify.  It was
         such an opaque mess and it's still not great, but it's
         better.
      
      6. Simplify the uo_expected field of TypeEqOrigin.  Richard
         had generatlised it to a ExpType, but it was almost always
         a Check type.  Now it's back to being a plain TcType which
         is much, much easier.
      
      7. Improve error messages by refraining from skolemisation when
         it's clear that there's an error: see
         TcUnify Note [Don't skolemise unnecessarily]
      
      8. Type.isPiTy and isForAllTy seem to be missing a coreView check,
         so I added it
      
      9. Kill off tcs_used_tcvs.  Its purpose is to track the
         givens used by wanted constraints.  For dictionaries etc
         we do that via the free vars of the /bindings/ in the
         implication constraint ic_binds.  But for coercions we
         just do update-in-place in the type, rather than
         generating a binding.  So we need something analogous to
         bindings, to track what coercions we have added.
      
         That was the purpose of tcs_used_tcvs.  But it only
         worked for a /single/ iteration, whereas we may have
         multiple iterations of solving an implication.  Look
         at (the old) 'setImplicationStatus'.  If the constraint
         is unsolved, it just drops the used_tvs on the floor.
         If it becomes solved next time round, we'll pick up
         coercions used in that round, but ignore ones used in
         the first round.
      
         There was an outright bug.  Result = (potentialy) bogus
         unused-constraint errors.  Constructing a case where this
         actually happens seems quite trick so I did not do so.
      
         Solution: expand EvBindsVar to include the (free vars of
         the) coercions, so that the coercions are tracked in
         essentially the same way as the bindings.
      
         This turned out to be much simpler.  Less code, more
         correct.
      
      10. Make the ic_binds field in an implication have type
            ic_binds :: EvBindsVar
          instead of (as previously)
             ic_binds :: Maybe EvBindsVar
          This is notably simpler, and faster to use -- less
          testing of the Maybe.  But in the occaional situation
          where we don't have anywhere to put the bindings, the
          belt-and-braces error check is lost.  So I put it back
          as an ASSERT in 'setImplicationStatus' (see the use of
          'termEvidenceAllowed')
      
      All these changes led to quite bit of error message wibbling
      3f5673f3
  11. 20 Apr, 2016 1 commit
    • Simon Peyton Jones's avatar
      SCC analysis for instances as well as types/classes · 353d8ae6
      Simon Peyton Jones authored
      This big patch is in pursuit of Trac #11348.
      
      It is largely the work of Alex Veith (thank you!), with some
      follow-up simplification and refactoring from Simon PJ.
      
      The main payload is described in RnSource
        Note [Dependency analysis of type, class, and instance decls]
      which is pretty detailed.
      
      * There is a new data type HsDecls.TyClGroup, for a strongly
        connected component of type/class/instance/role decls.
      
        The hs_instds field of HsGroup disappears, in consequence
      
        This forces some knock-on changes, including a minor
        haddock submodule update
      
      Smaller, weakly-related things
      
      * I found that both the renamer and typechecker were building an
        identical env for RoleAnnots, so I put common code for
        RoleAnnotEnv in RnEnv.
      
      * I found that tcInstDecls1 had very clumsy error handling, so I
        put it together into TcInstDcls.doClsInstErrorChecks
      353d8ae6
  12. 29 Mar, 2016 1 commit
  13. 23 Mar, 2016 1 commit
  14. 24 Feb, 2016 1 commit
    • eir@cis.upenn.edu's avatar
      Address #11471 by putting RuntimeRep in kinds. · d8c64e86
      eir@cis.upenn.edu authored
      See Note [TYPE] in TysPrim. There are still some outstanding
      pieces in #11471 though, so this doesn't actually nail the bug.
      
      This commit also contains a few performance improvements:
      
      * Short-cut equality checking of nullary type syns
      
      * Compare types before kinds in eqType
      
      * INLINE coreViewOneStarKind
      
      * Store tycon binders separately from kinds.
      
      This resulted in a ~10% performance improvement in compiling
      the Cabal package. No change in functionality other than
      performance. (This affects the interface file format, though.)
      
      This commit updates the haddock submodule.
      d8c64e86
  15. 12 Feb, 2016 1 commit
    • Simon Peyton Jones's avatar
      Improve pretty-printing of HsWrappers · d0846243
      Simon Peyton Jones authored
      Reduces un-neede parens.
      
      Also -fprint-typechecker-elaboration now makes type applications
      and casts in expressions also appear.  (Previously those were
      confusingly controlled by -fprint-explicit-coercions.)
      d0846243
  16. 18 Jan, 2016 1 commit
    • Simon Peyton Jones's avatar
      Refactoring on IdInfo and system derived names · ec8a188a
      Simon Peyton Jones authored
      Some modest refactoring, triggered in part by Trac #11051
      
      * Kill off PatSynId, ReflectionId in IdDetails
        They were barely used, and only for pretty-printing
      
      * Add helper function Id.mkExportedVanillaId, and use it
      
      * Polish up OccName.isDerivedOccName, as a predicate for
        definitions generated internally by GHC, which we
        might not want to show to the user.
      
      * Kill off unused OccName.mkDerivedTyConOcc
      
      * Shorten the derived OccNames for newtype and data
        instance axioms
      
      * A bit of related refactoring around newFamInstAxiomName
      ec8a188a
  17. 24 Dec, 2015 1 commit
    • eir@cis.upenn.edu's avatar
      Visible type application · 2db18b81
      eir@cis.upenn.edu authored
      This re-working of the typechecker algorithm is based on
      the paper "Visible type application", by Richard Eisenberg,
      Stephanie Weirich, and Hamidhasan Ahmed, to be published at
      ESOP'16.
      
      This patch introduces -XTypeApplications, which allows users
      to say, for example `id @Int`, which has type `Int -> Int`. See
      the changes to the user manual for details.
      
      This patch addresses tickets #10619, #5296, #10589.
      2db18b81
  18. 17 Dec, 2015 1 commit
  19. 15 Dec, 2015 1 commit
    • Ben Gamari's avatar
      Narrow scope of special-case for unqualified printing of names in core libraries · e2c91738
      Ben Gamari authored
      Commit 547c5971 modifies the
      pretty-printer to render names from a set of core packages (`base`,
      `ghc-prim`, `template-haskell`) as unqualified. The idea here was that
      many of these names typically are not in scope but are well-known by the
      user and therefore qualification merely introduces noise.
      
      This, however, is a very large hammer and potentially breaks any
      consumer who relies on parsing GHC output (hence #11208). This commit
      partially reverts this change, now only printing `Constraint` (which
      appears quite often in errors) as unqualified.
      
      Fixes #11208.
      
      Updates tests in `array` submodule.
      
      Test Plan: validate
      
      Reviewers: hvr, thomie, austin
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1619
      
      GHC Trac Issues: #11208
      e2c91738
  20. 11 Dec, 2015 1 commit
    • eir@cis.upenn.edu's avatar
      Add kind equalities to GHC. · 67465497
      eir@cis.upenn.edu authored
      This implements the ideas originally put forward in
      "System FC with Explicit Kind Equality" (ICFP'13).
      
      There are several noteworthy changes with this patch:
       * We now have casts in types. These change the kind
         of a type. See new constructor `CastTy`.
      
       * All types and all constructors can be promoted.
         This includes GADT constructors. GADT pattern matches
         take place in type family equations. In Core,
         types can now be applied to coercions via the
         `CoercionTy` constructor.
      
       * Coercions can now be heterogeneous, relating types
         of different kinds. A coercion proving `t1 :: k1 ~ t2 :: k2`
         proves both that `t1` and `t2` are the same and also that
         `k1` and `k2` are the same.
      
       * The `Coercion` type has been significantly enhanced.
         The documentation in `docs/core-spec/core-spec.pdf` reflects
         the new reality.
      
       * The type of `*` is now `*`. No more `BOX`.
      
       * Users can write explicit kind variables in their code,
         anywhere they can write type variables. For backward compatibility,
         automatic inference of kind-variable binding is still permitted.
      
       * The new extension `TypeInType` turns on the new user-facing
         features.
      
       * Type families and synonyms are now promoted to kinds. This causes
         trouble with parsing `*`, leading to the somewhat awkward new
         `HsAppsTy` constructor for `HsType`. This is dispatched with in
         the renamer, where the kind `*` can be told apart from a
         type-level multiplication operator. Without `-XTypeInType` the
         old behavior persists. With `-XTypeInType`, you need to import
         `Data.Kind` to get `*`, also known as `Type`.
      
       * The kind-checking algorithms in TcHsType have been significantly
         rewritten to allow for enhanced kinds.
      
       * The new features are still quite experimental and may be in flux.
      
       * TODO: Several open tickets: #11195, #11196, #11197, #11198, #11203.
      
       * TODO: Update user manual.
      
      Tickets addressed: #9017, #9173, #7961, #10524, #8566, #11142.
      Updates Haddock submodule.
      67465497
  21. 18 Nov, 2015 1 commit
    • msosn's avatar
      Fix inconsistent pretty-printing of type families · c61759d5
      msosn authored
      After the changes, the three functions used to print type families
      were identical, so they are refactored into one.
      
      Original RHSs of data instance declarations are recreated and
      printed in user error messages.
      
      RHSs containing representation TyCons are printed in the
      Coercion Axioms section in a typechecker dump.
      
      Add vbar to the list of SDocs exported by Outputable.
      Replace all text "|" docs with it.
      
      Fixes #10839
      
      Reviewers: goldfire, jstolarek, austin, bgamari
      
      Reviewed By: jstolarek
      
      Subscribers: jstolarek, thomie
      
      Differential Revision: https://phabricator.haskell.org/D1441
      
      GHC Trac Issues: #10839
      c61759d5
  22. 01 Nov, 2015 2 commits
    • Herbert Valerio Riedel's avatar
      Bump ghc-prim version to 0.5.0.0 (closes #11043) · 84bf1eba
      Herbert Valerio Riedel authored
      This also needs to update the primitive/vector submodules in order to
      relax upper bounds on ghc-prim.
      
      Like in f8ba4b55, a mass-rewrite in testsuite/ via
      
        sed -i s,ghc-prim-0.4.0.0,ghc-prim-0.5.0.0,g $(git grep -Fl 'ghc-prim-0.4.0.0')
      
      was performed.
      84bf1eba
    • Herbert Valerio Riedel's avatar
      Bump `base` version to 4.9.0.0 (closes #11026) · f8ba4b55
      Herbert Valerio Riedel authored
      This also relaxes a few upper bounds on base in the ghc.git repo;
      
      This required a mass-rewrite in testsuite/
      
        sed -i s,base-4.8.2.0,base-4.9.0.0,g $(git grep -Fl 'base-4.8.2.0')
      
      because it turns out the testsuite is still sensitive to package version
      changes.
      f8ba4b55
  23. 30 Oct, 2015 1 commit
    • Ben Gamari's avatar
      Generate Typeable info at definition sites · 91c6b1f5
      Ben Gamari authored
      This is the second attempt at merging D757.
      
      This patch implements the idea floated in Trac #9858, namely that we
      should generate type-representation information at the data type
      declaration site, rather than when solving a Typeable constraint.
      
      However, this turned out quite a bit harder than I expected. I still
      think it's the right thing to do, and it's done now, but it was quite
      a struggle.
      
      See particularly
      
       * Note [Grand plan for Typeable] in TcTypeable (which is a new module)
       * Note [The overall promotion story] in DataCon (clarifies existing
      stuff)
      
      The most painful bit was that to generate Typeable instances (ie
      TyConRepName bindings) for every TyCon is tricky for types in ghc-prim
      etc:
      
       * We need to have enough data types around to *define* a TyCon
       * Many of these types are wired-in
      
      Also, to minimise the code generated for each data type, I wanted to
      generate pure data, not CAFs with unpackCString# stuff floating about.
      
      Performance
      ~~~~~~~~~~~
      Three perf/compiler tests start to allocate quite a bit more. This isn't
      surprising, because they all allocate zillions of data types, with
      practically no other code, esp. T1969
      
       * T1969:    GHC allocates 19% more
       * T4801:    GHC allocates 13% more
       * T5321FD:  GHC allocates 13% more
       * T9675:    GHC allocates 11% more
       * T783:     GHC allocates 11% more
       * T5642:    GHC allocates 10% more
      
      I'm treating this as acceptable. The payoff comes in Typeable-heavy
      code.
      
      Remaining to do
      ~~~~~~~~~~~~~~~
      
       * I think that "TyCon" and "Module" are over-generic names to use for
         the runtime type representations used in GHC.Typeable. Better might
      be
         "TrTyCon" and "TrModule". But I have not yet done this
      
       * Add more info the the "TyCon" e.g. source location where it was
         defined
      
       * Use the new "Module" type to help with Trac Trac #10068
      
       * It would be possible to generate TyConRepName (ie Typeable
         instances) selectively rather than all the time. We'd need to persist
         the information in interface files. Lacking a motivating reason I
      have
         not done this, but it would not be difficult.
      
      Refactoring
      ~~~~~~~~~~~
      As is so often the case, I ended up refactoring more than I intended.
      In particular
      
       * In TyCon, a type *family* (whether type or data) is repesented by a
         FamilyTyCon
           * a algebraic data type (including data/newtype instances) is
             represented by AlgTyCon This wasn't true before; a data family
             was represented as an AlgTyCon. There are some corresponding
             changes in IfaceSyn.
      
           * Also get rid of the (unhelpfully named) tyConParent.
      
       * In TyCon define 'Promoted', isomorphic to Maybe, used when things are
         optionally promoted; and use it elsewhere in GHC.
      
       * Cleanup handling of knownKeyNames
      
       * Each TyCon, including promoted TyCons, contains its TyConRepName, if
         it has one. This is, in effect, the name of its Typeable instance.
      
      Updates haddock submodule
      
      Test Plan: Let Harbormaster validate
      
      Reviewers: austin, hvr, goldfire
      
      Subscribers: goldfire, thomie
      
      Differential Revision: https://phabricator.haskell.org/D1404
      
      GHC Trac Issues: #9858
      91c6b1f5
  24. 29 Oct, 2015 2 commits
    • Ben Gamari's avatar
      Revert "Generate Typeable info at definition sites" · bbaf76f9
      Ben Gamari authored
      This reverts commit bef2f03e.
      
      This merge was botched
      
      Also reverts haddock submodule.
      bbaf76f9
    • Ben Gamari's avatar
      Generate Typeable info at definition sites · bef2f03e
      Ben Gamari authored
      This patch implements the idea floated in Trac #9858, namely that we
      should generate type-representation information at the data type
      declaration site, rather than when solving a Typeable constraint.
      
      However, this turned out quite a bit harder than I expected. I still
      think it's the right thing to do, and it's done now, but it was quite
      a struggle.
      
      See particularly
      
       * Note [Grand plan for Typeable] in TcTypeable (which is a new module)
       * Note [The overall promotion story] in DataCon (clarifies existing stuff)
      
      The most painful bit was that to generate Typeable instances (ie
      TyConRepName bindings) for every TyCon is tricky for types in ghc-prim
      etc:
      
       * We need to have enough data types around to *define* a TyCon
       * Many of these types are wired-in
      
      Also, to minimise the code generated for each data type, I wanted to
      generate pure data, not CAFs with unpackCString# stuff floating about.
      
      Performance
      ~~~~~~~~~~~
      Three perf/compiler tests start to allocate quite a bit more. This isn't
      surprising, because they all allocate zillions of data types, with
      practically no other code, esp. T1969
      
       * T3294:   GHC allocates 110% more (filed #11030 to track this)
       * T1969:   GHC allocates 30% more
       * T4801:   GHC allocates 14% more
       * T5321FD: GHC allocates 13% more
       * T783:    GHC allocates 12% more
       * T9675:   GHC allocates 12% more
       * T5642:   GHC allocates 10% more
       * T9961:   GHC allocates 6% more
      
       * T9203:   Program allocates 54% less
      
      I'm treating this as acceptable. The payoff comes in Typeable-heavy
      code.
      
      Remaining to do
      ~~~~~~~~~~~~~~~
      
       * I think that "TyCon" and "Module" are over-generic names to use for
         the runtime type representations used in GHC.Typeable. Better might be
         "TrTyCon" and "TrModule". But I have not yet done this
      
       * Add more info the the "TyCon" e.g. source location where it was
         defined
      
       * Use the new "Module" type to help with Trac Trac #10068
      
       * It would be possible to generate TyConRepName (ie Typeable
         instances) selectively rather than all the time. We'd need to persist
         the information in interface files. Lacking a motivating reason I have
         not done this, but it would not be difficult.
      
      Refactoring
      ~~~~~~~~~~~
      As is so often the case, I ended up refactoring more than I intended.
      In particular
      
       * In TyCon, a type *family* (whether type or data) is repesented by a
         FamilyTyCon
           * a algebraic data type (including data/newtype instances) is
             represented by AlgTyCon This wasn't true before; a data family
             was represented as an AlgTyCon. There are some corresponding
             changes in IfaceSyn.
      
           * Also get rid of the (unhelpfully named) tyConParent.
      
       * In TyCon define 'Promoted', isomorphic to Maybe, used when things are
         optionally promoted; and use it elsewhere in GHC.
      
       * Cleanup handling of knownKeyNames
      
       * Each TyCon, including promoted TyCons, contains its TyConRepName, if
         it has one. This is, in effect, the name of its Typeable instance.
      
      Requires update of the haddock submodule.
      
      Differential Revision: https://phabricator.haskell.org/D757
      bef2f03e
  25. 25 Apr, 2015 1 commit
  26. 23 Mar, 2015 1 commit
  27. 20 Mar, 2015 1 commit
  28. 04 Nov, 2014 1 commit
  29. 09 Sep, 2014 1 commit
    • Herbert Valerio Riedel's avatar
      Bump `base` version to 4.8.0.0 for real · c6f502b2
      Herbert Valerio Riedel authored
      This commit updates several submodules in order to bump
      the upper bounds on `base` of most boot packages
      
      Moreover, this updates some of the test-suite cases which have
      version numbers hardcoded within.
      
      However, I'm not sure if this commit didn't introduce the following
      two test-failures
      
         ghc-api  T8628 [bad stdout] (normal)
         ghc-api  T8639_api [bad stdout] (normal)
      
      This needs investigation
      c6f502b2
  30. 29 Aug, 2014 1 commit
  31. 22 Aug, 2014 1 commit
    • Edward Z. Yang's avatar
      Do not zero out version number when processing wired-in packages. · 22520cd7
      Edward Z. Yang authored
      Summary:
      Previously, GHC would look for instances of wired-in packages in the
      in-memory package database and null out the version number.  This was
      necessary when the sourcePackageId was used to determine the linker
      symbols; however, we now use a package key, so only that needs to be
      updated.
      
      Long-term, we can remove this hack by ensuring that Cabal actually records
      the proper package key in the database.  This will also fix an unrelated
      hack elsewhere.
      
      Keeping version numbers means that wired in packages get rendered differently
      when output by GHC.  This is the source of all the test-case output changes.
      Signed-off-by: default avatarEdward Z. Yang <ezyang@cs.stanford.edu>
      
      Test Plan: validate
      
      Reviewers: hvr, austin
      
      Subscribers: simonmar, ezyang, carter
      
      Differential Revision: https://phabricator.haskell.org/D170
      22520cd7
  32. 31 Jul, 2014 1 commit
    • Simon Peyton Jones's avatar
      Complete work on new OVERLAPPABLE/OVERLAPPING pragmas (Trac #9242) · 1ae5fa45
      Simon Peyton Jones authored
      * Deprecate -XOverlappingInstances
      
      * Update test suite.  Several tests even had entirely unnecessary
        uses of -XOverlappingInstances
      
      * Update user manual with a careful description of the instance
        resolution story
      
      * Fix an outright bug in the handling of duplidate instances in GHCi,
        which are meant to silently overwrite the earlier duplicate. The
        logic was right for family instances but was both more complicated,
        and plain wrong, for class instances.  (If you are interested, the
        bug was that we were eliminating the duplicate from the InstEnv, but
        not from the [ClsInst] held in tcg_insts.)  Test is ghci044a.
      1ae5fa45
  33. 03 Jun, 2014 1 commit
    • Simon Peyton Jones's avatar
      Do pretty-printing of TyThings via IfaceDecl (Trac #7730) · b4856f9f
      Simon Peyton Jones authored
      All the initial work on this was done fy 'archblob' (fcsernik@gmail.com);
      thank you!
      
      I reviewed the patch, started some tidying, up and then ended up in a huge
      swamp of changes, not all of which I can remember now.  But:
      
      * To suppress kind arguments when we have -fno-print-explicit-kinds,
          - IfaceTyConApp argument types are in a tagged list IfaceTcArgs
      
      * To allow overloaded types to be printed with =>, add IfaceDFunTy to IfaceType.
      
      * When printing data/type family instances for the user, I've made them
        print out an informative RHS, which is a new feature. Thus
              ghci> info T
              data family T a
              data instance T Int = T1 Int Int
              data instance T Bool = T2
      
      * In implementation terms, pprIfaceDecl has just one "context" argument,
        of type IfaceSyn.ShowSub, which says
             - How to print the binders of the decl
               see note [Printing IfaceDecl binders] in IfaceSyn
             - Which sub-comoponents (eg constructors) to print
      
      * Moved FastStringEnv from RnEnv to OccName
      
      It all took a ridiculously long time to do.  But it's done!
      b4856f9f
  34. 09 Apr, 2014 1 commit
  35. 05 Apr, 2014 1 commit
    • eir@cis.upenn.edu's avatar
      Fix #8958. · d468cd37
      eir@cis.upenn.edu authored
      We now do role inference on stupid datatype contexts, allowing a
      lightweight role annotation syntax.
      d468cd37